The difference between open and closed headphones exists in the design of the housing and the required area of application.
The housing of closed headphones is designed in such a way that no ambient noise, or only very little, can be heard. At the same time, sound that people nearby might find annoying does not spill out from the headphones. For this reason, closed headphones are preferred for mobile use. A closed design is accomplished by using a continuous, sound-blocking material for the housing, while further measures are also taken inside the headphones.
If the housing has an open design, ambient noise can be heard. Accordingly, people who are nearby also hear the sound from the headphones. Open headphones offer the advantage that they sound a little more voluminous and detailed and give a better feeling of spaciousness. This also reduces the feeling of inside-head localisation. For these reasons, open headphones are particularly suitable for use on a hi-fi system or a headphone amplifier at home. The defining feature of the housing of open headphones is the fact that it has acoustically transparent areas, for example openings or acoustically transparent material.
Semi-open headphones are a mixture of both designs. However, it should be noted that semi-open headphones from our company tend to be more similar to the open design rather than the closed design.